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02-23-2021, 04:49 PM | #1 |
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SS/CS Start line Ratios
Hi,
Aussie Super stock question, where our class rules are closely in line with NHRA SS/CS, hence the title. We run a Proflite 3 speed behind a max effort, small cube, high rpm OEM iron headed wedge motor. Converter stall at just a bit over 8000rpm. Car weight is approx 3300lbs. After a reasonable break from racing we decided to change our first gear ratio, we're currently at 2.51 with a 6.0 rear gear, the car seems to launch harder with this gear but as a result the gear shifts are happening sooner and the run home in top gear (1/4 mile) is stretched, which seems to not be helping the e.t at the stripe. Unfortunately, the original ratios in the box were misplaced, but we're lead to believe they were around a 2.2 first. Hoping to pick a few a brains on which direction we should head with our ratio and if we should be aiming to head back to a numerically lower ratio? Thanks in advance for the help. |
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02-23-2021, 10:54 PM | #2 | |
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Re: SS/CS Start line Ratios
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-Ed
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Ed Carpenter 2005 Chevy Cobalt A/SM Race Engine Development |
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02-23-2021, 11:35 PM | #3 |
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Re: SS/CS Start line Ratios
Back when we ran that combination, we had a Pro-Trans with a 2.45/1.51 (E-2). I don't know if I was as fast as Ashton, but we made a few good runs over the years.
Our program made peak power around 9400 and if I'm not mistaken we had a converter stall around 8400. When we were in decent air we would cross at 10,200 if we were trying to run fast. Best of luck with your combo! Mike |
02-24-2021, 12:11 AM | #4 |
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Re: SS/CS Start line Ratios
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02-24-2021, 12:15 AM | #5 | |
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Re: SS/CS Start line Ratios
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Thanks for commenting, I've followed your car in the past and was certainly impressed with the results you achieved in ss/cs. The rpm at peak power of our combo is close to yours, out of interest what were you aiming for on the shift points? We might be a little conservative with ours from first impressions. Thanks for the help. |
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02-24-2021, 03:34 AM | #6 |
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Re: SS/CS Start line Ratios
The 2.45-1.45 is a real good ratio.
The % drop between gears is good. I heard rumors that was what the fastest CS car had in it. If you want to take a little low gear and a tiny bit of second gear out of it try putting a "F" in place of the "E". Makes it a 2.41/1.48 That is what is so nice about the pro flites. Watch the fast comp guys. A lot are in High at or before the 330....JS
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02-24-2021, 04:09 AM | #7 | |
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Re: SS/CS Start line Ratios
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02-24-2021, 09:55 AM | #8 | |
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Re: SS/CS Start line Ratios
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02-24-2021, 12:01 PM | #9 | |
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Re: SS/CS Start line Ratios
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By the way, the right converter is a game changer for performance. |
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02-24-2021, 03:14 PM | #10 |
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Re: SS/CS Start line Ratios
Yes solid lifters are still mandated with a maximum of .904 lifter size. Solid lifter makes them a little trickier to peak at the same RPMS as the SS/CS combos but they get close.
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